A series of quasi-multiple BIB designs from Hadamard matrices (Q2713654)

The paper presents a construction of a BIB design by a juxtaposition of multiple copies of two GD designs. By considering certain GD designs derived from Hadamard matrices, the authors obtain BIB designs of parameters NEWLINE\[NEWLINE(8t-1,\;2(8t-1),\;2(4t-1),\;4t-1,\;2(2t-1))\quad\text{and}\quad (4t-1,\;2(4t-1),\;2(2t-1),\;2t-1,2(t-1)),NEWLINE\]NEWLINE \(t \geq 2\). They prove that these designs are never duplicate, and relate their results to the table of BIB designs that has been published by \textit{R. Mathon} and \textit{A. Rosa} [Ars Comb. 30, 65-96 (1990; Zbl 0734.05012)].